scholarly journals Numerical studies of the effect of the temperature drop in the crucible - melt - cooled disk system on the shapes of crystallization fronts

2021 ◽  
Vol 2119 (1) ◽  
pp. 012084
Author(s):  
S A Kislitsyn ◽  
V S Berdnikov
Keyword(s):  
Mixed Convection ◽  
Crystallization Process ◽  
Crystallization Front ◽  
Temperature Drop ◽  
Water Layer ◽  
Triangular Grid ◽  
The Finite Element Method ◽  
Uniform Rotation ◽  
Disk System ◽  
Numerical Studies

Abstract The crystallization process on a cooled disk located on the free surface of a water layer is studied numerically. The influence of thermal gravitational-capillary and mixed convection on the shape of the crystallization front is investigated. In mixed convection modes, the speed of uniform rotation of the disk is set. The calculations were carried out in an axisymmetric formulation of the problem by the finite element method using an adaptive triangular grid and taking into account the latent heat of crystallization and the inverse dependence of density on temperature.

scholarly journals Investigations on Torsion of the Two-Chords Single Laced Members

2017 ◽  
Vol 25 (2) ◽  
pp. 147-160
Author(s):  
Paweł Lorkowski ◽  
Bronisław Gosowski
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
The Finite Element Method ◽  
Second Moment ◽  
Steel Columns ◽  
Numerical Studies ◽  
Traction Network ◽  
Railway Traction ◽  
Parametric Analyses ◽  
The Relationship

Abstract The paper presents experimental and numerical studies to determine the equivalent second moment of area of the uniform torsion of the two-chord steel single laced members. The members are used as poles of railway traction network gates, and steel columns of framed buildings as well. The stiffness of uniform torsion of this kind of columns allows to the determine the critical loads of the spatial stability. The experimental studies have been realized on a single - span members with rotation arrested at their ends, loaded by a torque applied at the mid-span. The relationship between angle of rotation of the considered cross-section and the torque has been determined. Appropriate numerical model was created in the ABAQUS program, based on the finite element method. A very good compatibility has been observed between experimental and numerical studies. The equivalent second moment of area of the uniform torsion for analysed members has been determined by comparing the experimental and analytical results to those obtained from differential equation of non-uniform torsion, based on Vlasov’s theory. Additionally, the parametric analyses of similar members subjected to the uniform torsion, for the richer range of cross-sections have been carried out by the means of SOFiSTiK program. The purpose of the latter was determining parametrical formulas for calculation of the second moment of area of uniform torsion.

scholarly journals An improved shear deformation theory for bending beams with symmetrically varying mechanical properties in the depth direction

2020 ◽  
Vol 231 (10) ◽  
pp. 4381-4395 ◽  
Author(s):  
Krzysztof Magnucki ◽  
Jerzy Lewinski ◽  
Ewa Magnucka-Blandzi
Keyword(s):  
Mechanical Properties ◽  
Shear Deformation ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
The Finite Element Method ◽  
Three Point Bending ◽  
Total Potential ◽  
Depth Direction ◽  
Numerical Studies ◽  
The Individual

Abstract The paper is devoted to simply supported beams under three-point bending. Their mechanical properties symmetrically vary in the depth direction. The individual shear deformation theory for beams of such features is proposed. Based on the principle of stationary total potential energy the differential equations of equilibrium are obtained. The system of the equations is analytically solved, and the shear coefficients and deflections of example beams are calculated. The solution is compared with other analytical results obtained with the use of another deformation function. Moreover, the bending problem of these beams is also numerically studied using the finite element method. Results of analytical and numerical studies are presented in Figures and Tables.

Dynamic Stability of a Cantilever Shaft-Disk System

1992 ◽  
Vol 114 (3) ◽  
pp. 326-329 ◽  
Author(s):  
Lien-Wen Chen ◽  
Der-Ming Ku
Keyword(s):  
Dynamic Stability ◽  
Dynamic Instability ◽  
Equations Of Motion ◽  
Beam Theory ◽  
The Finite Element Method ◽  
Disk System ◽  
Stability Behavior ◽  
Gyroscopic Moment ◽  
The Mathematical Model ◽  
Cantilever Shaft

The dynamic stability behavior of a cantilever shaft-disk system subjected to axial periodic forces varying with time is studied by the finite element method. The equations of motion for such a system are formulated using deformation shape functions developed from Timoshenko beam theory. The effects of translational and rotatory inertia, gyroscopic moment, bending and shear deformation are included in the mathematical model. Numerical results show that the effect of the gyroscopic term is to shift the boundaries of the regions of dynamic instability outwardly and, therefore, the sizes of these regions are enlarged as the rotational speed increases.

Uniform and Directed Crystallization of Deposited a­Si on Glass Substrates at Linear Velocities Of 1 to 20 Meters Per Second

1981 ◽  
Vol 4 ◽  
Author(s):  
D. Bensahel ◽  
G. Auvert ◽  
V. T. Nguyen ◽  
G. A. Rozgonyi
Keyword(s):  
Phase Boundary ◽  
Laser Power ◽  
Crystallization Process ◽  
Solid Phase ◽  
Crystallization Front ◽  
Continuous Furnace ◽  
Directed Crystallization ◽  
Glass Substrates ◽  
Explosive Crystallization ◽  
Scan Speed

ABSTRACTIt has been found that careful control of the laser power and scan speed will convert deposited a­Si into continuous lines of uniformly crystallized silicon. Two solid phase “explosive” crystallization front velocities of 1000 cm/sec and 1400 cm/sec have been experimentally determined by matching the laser scan velocity with the runaway a–c phase boundary. If solid phase explosive crystallization is suppressed by pre-annealing, then a liquid assisted runaway crystallization velocity of 220 cm/sec is observed, as well as a continuous furnace-like crystallization process at 250 cm/sec.

A Combination of Singular Cell-Based Smoothed Radial Point Interpolation Method and FEM in Solving Fracture Problem

2018 ◽  
Vol 15 (08) ◽  
pp. 1850079 ◽  
Author(s):  
Guiyong Zhang ◽  
Yaomei Wang ◽  
Yong Jiang ◽  
Yichen Jiang ◽  
Zhi Zong
Keyword(s):  
Strain Energy ◽  
Interpolation Method ◽  
The Finite Element Method ◽  
Radial Point Interpolation Method ◽  
Bound Solution ◽  
Numerical Studies ◽  
Radial Point Interpolation ◽  
Point Interpolation Method ◽  
Point Interpolation ◽  
Lower Bound Solution

The singular cell-based smoothed radial point interpolation method (CS-RPIM) has been previously proposed and shown good performance in solving fracture problems. Motivated from the fact that CS-RPIM performs over softly by providing an upper bound solution and the finite element method (FEM) is overly stiff by providing a lower bound solution, this work proposes a combination of singular CS-RPIM and FEM with a correlation coefficient [Formula: see text], and [Formula: see text] has been recommended through intensive numerical studies. Several numerical examples have been studied and the proposed method has been found perform quite well from both stress intensity factors and strain energy.

Structure and porosity of titanium scaffolds manufactured by selective laser melting

2018 ◽  
Vol 23 (1) ◽  
pp. 32-42
Author(s):  
Konstanty Skalski ◽  
Anna Makuch ◽  
Bartłomiej Wysocki ◽  
Krzysztof Jankowski ◽  
Wojciech Święszkowski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Simulations ◽  
Selective Laser Melting ◽  
Cell Cultures ◽  
Process Parameters ◽  
Structural Studies ◽  
The Finite Element Method ◽  
Laser Melting ◽  
Numerical Studies

The article presents the results of experimental and numerical studies of titanium scaffolds for cell cultures. In structural studies using scanning microscopy, the influence of incremental technology and technological process parameters on the shape and the size of the designed pores was analyzed. The designed constructions of various sizes and pore shapes were verified for strength using numerical simulations by the finite element method (FEM).

Vibro-Impact Responses of a Tube with Tube-Baffle Interaction

1978 ◽  
Vol 5 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Y.S. Shin ◽  
D.E. Sass ◽  
J.A. Jendrzejczyk
Keyword(s):  
Heat Exchangers ◽  
Impact Response ◽  
Elastic Contact ◽  
Baffle Plate ◽  
The Finite Element Method ◽  
Linear Elastic ◽  
Numerical Studies ◽  
Vibrational Characteristics ◽  
Manufacturing Tolerances ◽  
Good Agreement

The relatively small, inherent tube-to-baffle hole clearances associated with manufacturing tolerances in heat exchangers affect the vibrational characteristics and the response of the tube. Numerical studies were made to predict the vibro-impact response of a tube with tube-baffle interaction. The finite element method has been employed with a non-linear elastic contact spring-dashpot to model the effect of the relative approach between the tube and the baffle plate. The numerical analysis results are in reasonably good agreement with those of the experiments.

Study of the Transmission of Ultrasonic Guided Wave at the Junction of Two Different Elastic Plates with the Presence of a Defect

2011 ◽  
Vol 482 ◽  
pp. 21-29
Author(s):  
Taoufiq Belhoussine Drissi ◽  
Bruno Morvan ◽  
Mihai Predoi ◽  
Jean Louis Izbicki ◽  
Pascal Pareige
Keyword(s):  
Lamb Waves ◽  
Guided Wave ◽  
Elastic Plates ◽  
The Finite Element Method ◽  
Reflection And Transmission ◽  
Modal Approach ◽  
Limit Value ◽  
Numerical Studies ◽  
Ultrasonic Guided Wave ◽  
Orthogonality Relations

We are interested in a right junction of two plates of different materials (aluminum and copper) placed in contact edge to edge. The aim of this study is the interaction of Lamb waves with a defect located at the junction. The reflection and transmission of the fundamental symmetrical S0 wave is analyzed. The theoretical coefficients of reflection and transmission are obtained by a multi-modal approach based on the orthogonality relations involving different modes. Using the Finite Element Method (FEM), we estimate the limit value of the ratio between the dimension of the defect and the thickness of the structure, for which the multi-modal approach is applicable. In experimental and numerical studies, it is also brought to light the effects of diffraction by the defect.

scholarly journals ANALYTICAL AND NUMERICAL STUDIES OF THE STRESS-STRAIN STATE OF ROUND PLATES ON AN ELASTIC BASE WITH A VARIABLE BED COEFFICIENT

2020 ◽  
Author(s):  
Krutii Yurii ◽  
Surianinov Mykola ◽  
Soroka Mykola ◽  
Karnauhova Ganna
Keyword(s):  
Strain State ◽  
Elastic Base ◽  
Variable Coefficients ◽  
The Finite Element Method ◽  
Round Plate ◽  
Stress Strain ◽  
The Third ◽  
Stress Strain State ◽  
Numerical Studies ◽  
Elastic Resistance

The results of the study of the stress-strain state of a circular plate of constant cylindrical stiffness lying on an elastic foundation with a variable coefficient of elastic resistance are presented. Eight calculation options are considered − four each for a concrete round slab and for a steel round plate − under two conditions of fastening (hinged and rigid along the entire contour) and two laws of variation of the bed coefficient (according to the linear law and according to the law of the concave parabola). To solve the problem, the authors applied a general analytical method for solving differential equations with variable coefficients. The finite element method is used to verify the results. Comparison shows that the results coincide very well in deflections, differing in the third or fourth decimal places, and somewhat worse − in moments.

Automatic Mesh Generation on Annular Profiles With Geometric Constraints

1991 ◽  
Author(s):  
M. Sharma ◽  
J. Rodriguez ◽  
N. Langrana
Keyword(s):  
Geometric Constraints ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Mesh Generator ◽  
Cad System ◽  
Numerical Studies ◽  
Efficient Performance ◽  
Mesh Density ◽  
Automatic Mesh ◽  
Effective Analysis

Abstract The Finite Element Method (FEM) has been recognized as one of the most effective analysis method for complicated domains. Unfortunately, any practical application of FEM requires extensive amount of input data. General pre-processors usually require a large amount of user defined information. Therefore, in some particular applications, where more specific options are needed, a special mesh generator in required. In this paper we present an automatic mesh generator for annular models with inherent geometric constraints, such as fiber orientation in composite-like structures/systems. The developed generator is designed to generate 3-D meshes with minimal users’ input and effort, and it can be used in conjunction with almost any CAD system or FEM software. The code is particularly useful for efficient performance of numerical studies relating mesh density and convergence.

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